Tappet for internal-combustion engines



TAPPET FOR INTERNAL COMBUSTION ENGINES Filed June '7, 1924 WITNESSINVENTOR,

Patented July 5, 1927.

UITED STATES WILLIAM STEVENSON, OF MORRIS'IOWN, NEW JERSEY.

TAPPET FOR INTERNAL-COMBUSTION ENGINES.

Application filed June 7,

This invention contemplates an improved tappet for imparting actuationto the valve of an internal combustion engine, the construction beingsuch that the tappet is readily adjustable by a single person, theordinary tappet usually requiring two persons three hands-to effect itsadjustment. The improved tappet includes a' body member, a head memberhaving a screw-thread conio nection with the body member whose axis islengthwise of the tappet to efi'ect alteration in the length of thelatter on turning the head member, and a spring-actuated keeper splinedto one of said members, as the body member. and having a disengageableinterlock with the other. In adjusting, the keeper is pushed out ofengagement with the mem-- ber with which it is interlocked, tensioningthe spring, and said member is turned rela- Zll tively to the othermember. In order, in

this operation, to impose a desirable brake or drag on the head memberand to hold it precisely where it is thus adjusted until themanipulation of the parts is completed by allowing the keeper to returnto locking position, the invention also includes means to frictionallyresist the turning of said member; this means may also serve, when theinterlock is afforded by intermeshing teeth having sloping surfaces, asan auxiliary to the spring-actuated keeper to resist possible turning ofsaid member when the tappet is in action.

In the drawing,

Fig. 1 is a side elevation of the improved tappet and fragments of thecam and valvestem of an internal combustion engine;

Fig. 2 is a view of the improved tappet mainly in vertical centralsection:

Fig. 3 is a side elevation, partly in section, and underneath plan ofthe head member;

Fig. 4: is a top plan, vertical section -and underneath plan of thekeeper;

Fig. 5 is a plan of the body member; and

Fig. 6 shows a part of the means to frictionally resist turning of thehead member.

The body member a of the improved tappet is cylindrical and has theusual basal flange a; at its upper end there is a reduced extension aand from its upper end.

extends downwardly through the extension a bore 6 closed at the bottomand internally threaded. The extension is flattened, preferably atopposite sides, as indicated at a proper 0 to receive a wrench and anaxial The head member 0 has a hexagonal headv 1924. Serial No. 718,433.

threaded depending stem 0 It also has a depending flange c spaced fromthe stem and serrated at its edge.

(Z is the keeper consisting of a 'disk having an upper peripheral flanged serrated at its edge and formed at its lower side with a recess 03 Thedisk has a central hole d formed with two opposite straight sides, asshown in Fig. 4:, and being otherwise shaped the same as stem 0 in plan.

e is a spiral spring of a diameter to be received in the recess (Z andreceive the extension a of said body member.

The foregoing parts are assembled as shown in Fig. 2, the head memberhaving its stem screwed into the extension of the body member, and thespring and keeper being fitted over said extension and the formerbearing against the enlarged lower part of the body member and holdingthe flange of the keeper bearingagainst the flange of the head memberwith their serrations or teeth interlocked with each other.

The tappet being positioned in'the engine between the stem '5 ofa valveand a cam 7' for actuating the valve, adjustment of the height of thetappet is eflected by depressing the keeper until the teeth thereof andof the head 0 clear each other and then turning the head with a wrenchapplied to its head proper 0. Since the keeper is in effect splined tothe body member (1 because its hole d fits the flat-sided extension (1,of the body member, when the keeper is now released so that its teethinterlock with those of the head member the keeper will hold the headmember where adjusted.

The lower end of the stem 0 has a conical recess f and may be split, asat f, in two intersecting planes. This recess receives a conicalplug 9having a stem 9, the lug being subject to the pressure of a spira springh interposed between the plug and the bottom of the bore 7) andreceiving at its upper end the stem of the plug, as shown in Fig. 2.This means for imposing frictional resistance to the turning of the headmember is desirable in obtaining a nice adjustment of, the latter, whichotherwise might 105 be inadvertently turned more or less one Way or theother after the adjustment has been effected but before the keeper isreleased to lock the head in position. It also serves, especially wherethe surfaces of the teeth or serrations are inclined, as an auxiliary tothe keeper in holding the head against turning I what I claim as new anddesire to secure Letters Patent'is as an incident of the reciprocatingmotion of. the tappet when :in action. Good frictional resistance isobtained by recessing and splitting the stem as described, and to thisend the taper of the plug 9 should be such as to cause expansion of thesplit portion of said stem.

Having thus fully described my invention,

1. An engine tappet including'a body member, a head member having athreaded connection with the body member, spring including means,interposed between said members and acting lengthwise of the tappet, toreleasably hold the head member against turning relatively to the bodymemher, and a friction brakemeans interposed between said members.

2. An engine tappet including a body member, a head member having athreaded connection with the body member, springin said recess and aspring interposed betwen said plug and the other member.

In testimony whereof I affix my signature.

WILLIAM STEVENSON.

